1. Field of the Invention
This invention relates to polycyclic amides of phosphorous acid. More specifically, it relates to bicyclic and tricyclic triamides of phosphorous acid and their use as flame retardants for cotton.
2. Description of the Prior Art
Polycyclic phosphorous triamides and their carbon analogs are known, but no phosphorous triamides in which the amide nitrogens are annular hetero atoms in a single large ring are known. The closest prior art references are:
1. Stetter and Bremen, Chem, Ber., 106, 2523 (1973), disclose the following reaction: ##STR3##
2. Laube et al., Inorg. Chem., 6, 173 (1967), disclose the transamidation reaction ##STR4##
3. Petrov et al., U.S.S.R. 144,172 (1962) (C.A., 57, 5583 (1962)), disclose transamidation of phosphorous amides by heating with amines of higher boiling point than those of the amines that composed the amide groups of the initial amides.